A book about a posthuman society - most people exist as virtual entities in the datanet of vast supercomputers - dealing with astrophysical disaster striking the earth and then trying to explore parallel universes. Lots of mathematical theory, but rather short on interesting characters or plot resolution; perhaps a bit like Stapledon without his trademark breathlessness. Glad to have finally ticked this off my list.

It's a great book, my favourite of Egan's. Notice how the entire plot runs with almost no conflict or drama between the characters—the few disagreements (like whether to send probes into the oceans of Orpheus) are easily solved democratically.